1. Field of the Invention
The present invention relates generally to a mechanism for holding a circuit board and, more particularly, to mechanisms for inserting and removing a circuit board to/from a housing.
2. Description of Related Art
Conventional electronic systems typically contain a number of similarly-functioning circuit boards, which may also be referred to as boards or cards. Such a system, shown in FIG. 1, includes a housing 100 containing a back plane, or some other electronic architecture (not shown), for receiving and interconnecting the cards. These cards conventionally plug into connectors located on a back plane or mid plane. The housing 100 typically contains a number of racks 110 to hold the cards. An example of such a system is a rack-mounted communication system which contains a number of communication interface cards.
Each circuit card is typically affixed to a card carrier, that fits into corresponding receiving hardware (not shown) in the housing 100. The receiving hardware facilitates card insertion and retention. One way of configuring such a system is to screw or bolt the card carrier onto the receiving hardware, after the circuit card""s connector has been inserted into a corresponding connector. In this manner, the screw or bolt prevents the two connectors from becoming disconnected via vibration, insertion or removal of adjacent cards, etc. To enclose the card carrier, a faceplate is typically used, which may attach to the card carrier, or directly to the housing 100. Such faceplates may have holes for connectors to extend through to connect to wires or cables, and transparent windows for indicator lights or other visual displays.
Another way of configuring an electronics system recognizes that cards may need to be replaced with some frequency. For example, so-called hot-swappable cards and interfaces allow insertion and removal of cards without turning off the power to the electronics system. In such an arrangement, the receiving hardware in the housing 100 typically includes a slot for guiding and aligning the card carrier. The card carrier is pushed into the slot until the card""s connector and the corresponding connector on the back plane or mid plane are in firm contact. Typically, the faceplate must be inserted with such force that the card cannot be moved into the housing any further. The faceplate in this arrangement typically includes a handle or gripping surface, so that a technician can pull the card back out when desired.
This conventional arrangement, however, relies on an operator to determine by xe2x80x9cfeelxe2x80x9d when insertion is complete. Also, a small handle on a faceplate may be insufficient to overcome the holding friction of the card""s connector. In both the insertion and removal scenarios, the operator may be required to xe2x80x9cjigglexe2x80x9d or jar the card carrier to obtain complete insertion or removal of the card. Such fiddling increases the time needed to swap cards and does not guarantee fall card insertion. It may also increase the likelihood of bent connector pins and other damage to the circuit card. Also, the card is only held in place by the friction of its connector with the corresponding receiving connector. When vibration or other jarring occurs, cards held in place by friction may become unseated and lose proper electrical connection.
As a result, a need exists for a card carrier that facilitates insertion and removal, while securely retaining the card once it has been inserted.
Systems and methods consistent with the present invention address this and other needs via circuit card carriers that facilitate the insertion and removal of corresponding circuit cards into and out of a housing.
In accordance with the purpose of the invention as embodied and broadly described herein, a removable apparatus for carrying a circuit board includes a carrying plate having a notch to receive a stationary pin and a faceplate connected to one end of the carrying plate. A cam is connected to the carrying plate to rotate and act on the pin to move the apparatus relative to the pin. A linkage is connected to the cam and extends through the faceplate, connecting to a lever on an opposite side of the faceplate from the cam that facilitates insertion and removal of the apparatus from a housing.
In another implementation consistent with the present invention, a circuit card carrier for insertion into and removal of a circuit card from an enclosure having a stationary pin includes a carrying plate having a notch therein to receive the stationary pin. A cam is connected to the carrying plate so that it may rotate, and the cam has a first surface to act on the pin during removal and a second surface to act on the pin during insertion. A linkage is connected to the cam and to an actuator. Movement of the actuator in conjunction with the linkage rotates the cam to facilitate insertion and removal of the carrier from the enclosure.